Plasma Lipids-Dependent Vitamin E Metabolism During Dynamic Hyperlipidemia
Plasma Lipids-dependent Vitamin E Metabolism During Dynamic Hyperlipidemia
Background:
Obesity is known to lead to diseases such as diabetes and high cholesterol (or fats) in the blood (hyperlipidemia). But no one knows why. Researchers think that high levels of fat in the blood may block important nutrients, such as vitamin E, from reaching places they are needed in the body.
Objective:
To learn how high-fat meals affect levels of vitamin E in the blood.
Eligibility:
People aged 18 to 65 with high blood fat levels. Healthy volunteers are also needed.
Design:
Participants will have 3 or 4 clinic visits in 3 months. The last visit will require them to stay in the clinic for 2 nights.
Participants will be screened. They will have a physical exam and blood tests.
After this visit, all participants must stop taking any dietary supplements.
Those who use them must also stop taking any drugs to lower their blood sugar and blood fats. These participants will have an extra visit for blood tests after 60 days.
The next visit will include 2 imaging scans:
Magnetic resonance imaging (MRI) of the abdomen. This scan will check for fat in the liver.
Dual-energy X-ray absorptiometry (DEXA). This scan measures the levels of body fat.
On day 1 of the clinic stay, participants will have 2 set meals, with nothing but water after 10 pm.
On day 2, they will drink high-fat shakes at 8 am, noon, and 4 pm. They will have blood draws every hour for 17 hours, and then every 2 hours until 7 am. The blood will be taken from a tube inserted into a vein and left in place for the day.
On day 3, they will go home.
Panoramica dello studio
Stato
Stato
Condizioni
Condizioni
Intervento / Trattamento
Intervento / Trattamento
Descrizione dettagliata
Study Description:
A controlled interventional study of effects of postprandial hypertriglyceridemia from three consecutive high-fat vitamin E-stripped meals on the dynamics of plasma vitamin E concentrations in subjects with baseline normo- and hyperlipidemia, to explore the concept of vitamin E sequestration by fats in plasma.
Objectives:
Primary Objective: Compare effects of postprandial hypertriglyceridemia (PHTG) on plasma/lipoprotein vitamin E dynamics in subjects between baseline normo- and hyperlipidemia.
Secondary Objectives: Compare effects of postprandial hypertriglyceridemia (PHTG) on other fat-soluble vitamins (gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A]) and related vitamers (beta-carotene, lycopene lutein/zeaxanthin) between subjects with baseline normo- and hyperlipidemia.
Tertiary/Exploratory Objectives:
- Compare effects of individual high-fat meals on the dynamics of vitamin E, gamma-tocopherol, phylloquinone [K1], menaquinone [K2], 25-OH vitamin D, retinol [A], and other carotenoids between subjects with baseline normo- and hyperlipidemia.
- Compare effects of postprandial hypertriglyceridemia (PHTG) and resultant vitamin E dynamics on: red blood cell (RBC) membrane deformability, fluidity, and oxygen exchange capacity (p50); RBC vitamin E, plasma vitamin C, plasma dehydroascorbic acid; fasting glucose and insulin; oxidized LDL, coenzyme Q10, and plasma adipokine profile between subjects with baseline normo- and hyperlipidemia;
- Explore effects of postprandial hypertriglyceridemia on small RNAs including microRNAs, tRNAs, and PIWI-interacting RNAs.
- Explore the influence of genetic variance on the metabolism of vitamin E and other fat-soluble vitamins and related vitamers in subjects with baseline normo- and hyperlipidemia.
Endpoints:
Primary Endpoint: AUC (Area Under the Curve) of vitamin E plasma from hour 1 to hour 23, by cohort.
Secondary Endpoints: AUC of gamma-tocopherol, phylloquinone [K1], menaquinone [K2], 25-OH vitamin D and retinol [A] from hour 1 to hour 23, by cohort.
Tertiary/Exploratory Endpoints:
- Between the timepoints that reflect consuming 3 high-fat meals, AUC of vitamin E, gamma-tocopherol, phylloquinone [K1], menaquinone [K2], 25-OH vitamin D, retinol [A], and other carotenoids will be separately calculated for each participant.
- Over the course of inpatient visit, RBC membrane deformability/fluidity, p50, RBC vitamin E, plasma vitamin C, plasma dehydroascorbic acid, blood glucose, insulin, c-peptide, oxidized LDL, coenzyme Q10 and serum adipokine profiles in each subject.
- Over the course of inpatient visit, small RNAs including microRNAs, tRNAs, and PIWI-interacting RNAs.
- Genetic variance (single nucleotide polymorphisms, SNPs)- dependent change in lipid-soluble vitamin dynamics over the course of inpatient visit in each subject.
Tipo di studio
Tipo di studio
Iscrizione (Stimato)
Iscrizione
Fase
Fase
- Non applicabile
Contatti e Sedi
Contatto studio
Contatto studio
- Nome: Robert D Shamburek, M.D.
- Numero di telefono: (301) 496-3460
- Email: bobs@mail.nih.gov
Backup dei contatti dello studio
- Nome: Katherine C Roskom, R.N.
- Numero di telefono: (301) 451-7094
- Email: katherine.roskom@nih.gov
Luoghi di studio
-
-
Maryland
-
Bethesda, Maryland, Stati Uniti, 20892
- National Institutes of Health Clinical Center
-
Contatto:
- NIH Clinical Center Office of Patient Recruitment (OPR)
- Numero di telefono: TTY dial 711 (800) 411-1222
- Email: ccopr@nih.gov
-
Contatto:
- Robert Shamburek, M.D.
- Numero di telefono: 301-496-3460
- Email: bobs@mail.nih.gov
-
-
Criteri di partecipazione
Criteri di ammissibilità
Criteri di ammissibilità
Età idonea allo studio
- Adulto
- Adulto più anziano
Accetta volontari sani
Descrizione
- INCLUSION CRITERIA
Cohort 1
- Males and females between the ages of 18 to 65
- BMI 18.5 - 26.9 kg/m^2
- Subject understands the protocol and provides written, informed consent in addition to a willingness to comply with specified follow-up instructions and evaluations
- Normotensive, not on medications for hypertension
- Not on glucose-lowering or lipid-lowing medications
- Screening labs with baseline HbA1c <5.7%, baseline fasting triglyceride < 150 mg/dL and LDL <100 mg/dL
- Liver fat <2%
Cohort 2
- Males and females between the ages of 18 to 65
- BMI >26 kg/m^2 and <36 kg/m^2
- Subject understands the protocol and provides written, informed consent in addition to a willingness to comply with specified follow-up instructions and evaluations.
- Screening labs with baseline HbA1c <= 7.5%, agree to be off or stop oral glucose-lowering medications (metformin), baseline fasting triglyceride < 500 mg/dL and LDL <190 mg/dL, agree to be off or stop oral lipid-lowing medications for 4-10 weeks prior to the inpatient visit.
- Liver fat <2%
EXCLUSION CRITERIA
- For women: pregnancy or currently breastfeeding
- Subjects <18-year-old. This age group has a broad spectrum of hormonal profiles, due to development and puberty, which significantly increases the heterogenicity of the study subjects.
- Subjects >65-year-old. This age group has significantly increased risk of cardiovascular diseases. To minimize the risk from temporarily suspending lipid- and glucose-lowering medications and stress from serial blood draws, we exclude these individuals.
- Heavy alcohol user (males with >2 drinks per day or >14 drinks per week; female with >1 drinks per day or >7 drinks per week)
- Current smoker, or former smoker who quit smoking <15 years ago
- Subjects with weight changes greater than 20% baseline body weight over the past 3 months
- Subjects with lactose intolerance unwilling to take lactase
- Subjects with type 1 diabetes
- Subjects with hemoglobin <11 g/dL or hematocrit <33%
- Subjects with abnormal liver function test results
- Subjects with liver fat >= 2% on abdominal MRI
- Subjects with a history of pancreatitis, diabetes ketoacidosis, hyperosmolar hyperglycemic state, advanced atherosclerosis, cardiovascular diseases, kidney diseases, or liver diseases
- Subjects with fat malabsorption including: history of gastrointestinal surgery, pancreatic insufficiency, inflammatory bowel disease, celiac disease, moderate-to-severe irritable bowel syndrome, and pathologic mutations impacting lipoprotein metabolism
- Subjects on glucocorticoids >1 week (not including topical glucocorticoids)
- Subjects with HIV
- Subjects with uncontrolled psychiatric and/or behavioral disorders
- Subjects taking diabetes medications other than metformin
- Anticipated surgery during the study period
- Subjects with severe medication-resistant claustrophobia
- Subjects who are unwilling to stop medications, vitamins and/or dietary supplements that investigators have requested to be held
- Subjects participating in any other clinical study without informing investigators
- Any other reason or clinical condition that the investigators judge would interfere with study participation and/or be unsafe for a participant or staff member
Piano di studio
Come è strutturato lo studio?
Dettagli di progettazione
- Scopo principale: Scienza basilare
- Assegnazione: Non randomizzato
- Modello interventistico: Assegnazione parallela
- Mascheramento: Nessuno (etichetta aperta)
Numero di armi
Armi e interventi
Gruppo di partecipanti / ArmGruppo di partecipanti / Arm |
Intervento / TrattamentoIntervento / Trattamento |
|---|---|
|
Comparatore attivo: Healthy subjects
Three consecutive high-fat vitamin E-stripped meals
|
Three consecutive high-fat vitamin E-stripped meals
|
|
Sperimentale: Subjects with hyperlipidemia
Three consecutive high-fat vitamin E-stripped meals
|
Three consecutive high-fat vitamin E-stripped meals
|
Cosa sta misurando lo studio?
Misure di risultato primarie
Misure di risultato primarie
Misura del risultato |
Misura Descrizione |
Lasso di tempo |
|---|---|---|
|
AUC (Area Under the Curve) of vitamin E plasma from hour 1 to hour 23 by cohort.
Lasso di tempo: From hour 1 to hour 23
|
Compare the effects of postprandial hypertriglyceridemia on plasma vitamin E dynamics in subjects between baseline normo- and hyperlipidemia.
|
From hour 1 to hour 23
|
Misure di risultato secondarie
Misure di risultato secondarie
Misura del risultato |
Misura Descrizione |
Lasso di tempo |
|---|---|---|
|
AUC of gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A] from hour 1 to hour 23 by cohort.
Lasso di tempo: From hour 1 to hour 23
|
Compare the effects of postprandial hypertriglyceridemia on other fat-soluble vitamins (gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A]) and related vitamers (beta-carotene, lycopene lutein/zeaxanthin) in subjects between baseline normo- and hyperlipidemia.
|
From hour 1 to hour 23
|
Collaboratori e investigatori
Sponsor
Sponsor
Investigatori
Investigatori
- Investigatore principale: Robert D Shamburek, M.D., National Heart, Lung, and Blood Institute (NHLBI)
Pubblicazioni e link utili
Collegamenti utili
Studiare le date dei record
Studia le date principali
Inizio studio (Stimato)
Inizio studio
Completamento primario (Stimato)
Completamento primario
Completamento dello studio (Stimato)
Completamento dello studio
Date di iscrizione allo studio
Primo inviato
Primo inviato
Primo inviato che soddisfa i criteri di controllo qualità
Primo inviato che soddisfa i criteri di controllo qualità
Primo Inserito (Effettivo)
Primo Inserito
Aggiornamenti dei record di studio
Ultimo aggiornamento pubblicato (Effettivo)
Ultimo aggiornamento pubblicato
Ultimo aggiornamento inviato che soddisfa i criteri QC
Ultimo aggiornamento inviato che soddisfa i criteri QC
Ultimo verificato
Ultimo verificato
Maggiori informazioni
Termini relativi a questo studio
Parole chiave
Termini MeSH pertinenti aggiuntivi
Altri numeri di identificazione dello studio
Altri numeri di identificazione dello studio
- 10002623
- 002623-H
Piano per i dati dei singoli partecipanti (IPD)
Hai intenzione di condividere i dati dei singoli partecipanti (IPD)?
Descrizione del piano IPD
Periodo di condivisione IPD
Criteri di accesso alla condivisione IPD
Tipo di informazioni di supporto alla condivisione IPD
- STUDIO_PROTOCOLLO
- ICF
Informazioni su farmaci e dispositivi, documenti di studio
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